BMW M60B40 Engine

1. Specifications
2. Overview, problems
3. Performance tuning

M60B40 Specs

BMW M60B40 engine reliability, problems and repair

For big sedans and sports coupes, BMW released M60-series engines with a V8 configuration, and these motors occupied a position in between the straight-6 M50 and the V12 M73. The M60B40 became the primary engine in that series and replaced the BMW M30B35. The more recent model M60B30 came out at the same time.
The cylinder block of M60B40 engines is aluminum, with a camber of 90 degrees, with Nikasil-coated cylinder sleeves and a cast iron crankshaft. At the end of 1994, the cylinder block was replaced with a more reliable one: an Alusil coating was applied to the cylinder walls, and new, modified pistons. The BMW M60 has bore spacing of 98 mm. and a connection rod length of 143 mm.

The cylinder block heads are aluminum, with 2 camshafts, 4 valves per cylinder, with hydraulic lifters attached. The diameter of the intake valves is 35 mm., that of the exhaust valves 30.5 mm. The specs of the stock camshafts for the BMW M60B40 are as follows: duration 246/242 deg, lift 9.7/9.4 mm. The throttle body diameter of the M60B40 is 70 mm.

For the M60, individual ignition coils were used, and a new intake manifold and a two-row timing chain, with a range of 120,000 – 150,000 miles (200,000 – 250,000 km.). The engines control block is a Bosch Motronic 3.3.

This motor is used in BMWs with an index of 40i.

In 1996 the M60B40 was replaced by the improved, updated M62B44.

BMW M60B40 engine problems and drawbacks

1. Rough idle. In most cases the problem is solved by regulation of fuel distribution phases. It is also a good idea to check cylinder compression, positive crankcase ventilation, and the oxygen sensors.
2. High oil consumption. The defect can be resolved by changing the PCV valve, or the valve stem seals together with the piston rings. If the cylinders are worn, you should buy a new cylinder block or perform a sleeving operation.
Besides, in countries where only low-quality gasoline is available, the cylinder block with its Nikasil coating gets worn and loses cylinder compression, and therefore it is desirable to buy a BMW M60 dating from after 1994, which will not have this problem.

Service for a BMW M60 engine is somewhat more expensive than for the more recent M50, and it also gets worse gas mileage. And additional factors are the age of the motor, a high odometer reading, and excessive use by previous owners. In view of this, buying an M60 engine may not be the best idea, you’d better buy an M62B44 or M62B46.

BMW M60 engine number location

The motor number is located on the right side, near the third cylinder, by the coolant drain plug.

BMW M60 B40 engine tuning

The M60B40 Chip. Cams

Proper tuning for an M60B40 engine should start with the purchase of a throttle body from an M62B44 (non-Vanos), a sport air filter, and a cat-back performance exhaust system. After the ECU is tuned, your engine will display a horsepower of ~300 HP.
If you buy performance camshafts (duration 258/258 deg, lift 10.5/10.5 mm.), then the M60B40 can reach more than 320 HP. This is the optimal configuration and the easiest one; it will equip your car for convenient city driving, without significant problems.

M60B40 Supercharger. Turbo

An alternative route can be the installation of a supercharger. For this a supercharger kit (for instance the ESS VT1) must be purchased; these devices include everything needed for quick “bolt-on” installation onto the stock internals of the M60B40. The maximum pressure boost for such kits is about 7 psi (0.5 bar), which means you don’t have to worry about the pistons or rods. Furthermore, with 7 psi you can get about 400 HP, which will allow high speeds.
You can build a turbo on an M60B40 base, but it will take a lot of work and a lot of money. It will be a lot simpler to buy a BMW M5 E39 and enjoy a powerful engine right away.

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